Currently, nanotips are of strong interest for applications such as field emission and near-field microscopy. Nano- and microtips have been demonstrated in Si using anisotropic wet chemical etching (see V. V. Poborchii, T. Tada, T. Kanayama, “Optical properties of arrays of Si nanopillars on the (100) surface of crystalline Si”, Physica E, 7, 545, 2000). A nanotip AlxGa1-xAs/GaAs VCSEL, integrated with a photodetector, has also been demonstrated for near-field microscopy (see S. Khalfallah, C. Gorecki, J. Podlecku, M. Nishioka, H. Kawakatsu, Y. Arakawa, “Wet-etching fabrication of multilayer GaAlAs/GaAs microtips for scanning near-field microscopy”, Appl. Phys. A Materials Science and Processing, electronic publication, Springer-Verlag, Jun. 30, 2000). In traditional micro-tip field-emission devices, the wearing out of the tip due to radiation damage is a major reliability issue. Therefore, a wide bandgap semiconductor material would be preferred for field-emission. There have been reports on SiC nanowires by K. W. Wong et al. (see K. W. Wong, “Field-emission characteristics of SiC nanowires prepared by chemical-vapor deposition”, Appl. Phys. Lett., 75 (19), 2918, Nov. 8, 1999), and on GaN nanowires by Li et al. and Cheng et al. (see “Synthesis of aligned gallium nitride nanowire quasi-arrays”, Appl. Phys. A. Materials Science and Processing, electronic publication, Springer-Verlay, Aug. 9, 2000; G. S. Cheng, L. D. Zhang, Y. Zhu, G. T. Fei, L. Li, C. M. Mo, Y. Q. Mao, “Large-scale synthesis of single crystalline gallium nitride nanowires”, Appl. Phys. Lett., 75 (16), 2455, Oct. 18, 1999). However, such nanowires show random orientation and dimensions. For practical device applications, it is desired to have a highly oriented nanotip array that is built on a patterned area. Recently, there have been a few reports on the fabrication of self-assembled ZnO nanowire lasers (see J. C. Johnson, H. Yan, R. D. Schaller, L. H. Haber, R. J. Saykally, P. Yang, “Single nanowire lasers”, J. Physical Chemistry B, 105 (46), November 2001). ZnO is a wide bandgap semiconductor with a high excitonic binding energy (60 meV), hence can facilitate low-threshold stimulated emission at room temperature. This low-threshold is further enhanced in low-dimensional compound semiconductors due to carrier confinement. ZnO is found to be significantly more radiation hard than Si, GaAs, and GaN. Nanowires of ZnO, Si, SiC, and GaN have been grown using various methods such as vaporphase transport process as disclosed by J. C. Johnson et al (see J. C. Johnson, H. Yan, R. D. Schaller, L. H. Haber, R. J. Saykally, P. Yang, “Single nanowire lasers”, J. Physical Chemistry B, 105 (46), November 2001), chemical vapor deposition as shown by K. W. Wong et al (see K. W. Wong, “Field-emission characteristics of SiC nanowires prepared by chemical-vapor deposition”, Appl. Phys. Lett., 75 (19), 2918, Nov. 8, 1999), direct gas reaction as disclosed by Li et al (see “Synthesis of aligned gallium nitride nanowire quasi-arrays”, Appl. Phys. A. Materials Science and Processing, electronic publication, Springer-Verlay, Aug. 9, 2000; G. S. Cheng, L. D. Zhang, Y. Zhu, G. T. Fei, L. Li, C. M. Mo, Y. Q. Mao, “Large-scale synthesis of single crystalline gallium nitride nanowires”, Appl. Phys. Lett., 75 (16), 2455, Oct. 18, 1999), etc. In these methods, the growth temperatures were in very high range of 900° C. and above. This invention relates to a growth method to grow ZnO nanotips overcoming the deficiencies of prior methods.